$3,680
Waltham, Mass. , U.S.A., "Vanguard", Model 1908, No. 25340130, circa 1924.Very fine and very rare, 14K white gold-filled, keyless sidereal watch with 30-hour winding indicator and special hairspring. three-body, "bassine" by Keystone, screwed bezel and back , straight line engine-turned back, partially engraved with floral pattern 16 size, nickel, bridge caliber, damascened, 23 jewels, the top ones in gold settings, gold center wheel, adjusted to 6 positions, straight line lever escapement, cut-bimetallic compensation baance with gold screws, blued steel Breguet balance spring, OHLSON micrometric regulator.Engraved on ratchet wheel "Lossier Inner Terminal Hair Spring".Signed on the dial, case and movement. Dial signed "Sidereal", "BU. Aero. U.S. Navy G.S.T." (Bureau of Aeronautics - U.S. Navy, Greenwich Sidereal Times)Diam. 51.6 mm. Notes Sidereal time is the time it takes the earth to make one full revolution around its axis. Since in practice it can be measured as the Earth's rotation with respect to distant celestial objects, it is called sidereal or star time (sider = star in Latin). The sidereal day is 23 hours 56 minutes and 41 seconds long. There is one more day in a sidereal year than in a solar year. Sidereal time is used for precise astronomical observations.
Auctioneer:
Antiquorum
Date:
2001-11-28
